Tailpipe forming mechanism

ABSTRACT

A forming die is described for producing compound bends in tubing without removal from the machine or the use of special fixtures. This arrangement is achieved by providing cut-away sections for clearance of the compound bend adjacent to the die.

United States Patent 1191 Fazzani Jan. 29, 1974 TAILPIPE F ORMING MECHANISM 3,546,917 12/1970 [75] Inventor: Raymond John Fazzani, Pawtucket, 3,685,335 8/1972 1 Assignw ,Thq 9 5l g qq;Co p y; FOREIGN PATENTS OR APPLICATIONS Tomngton, 881,398 4/1943 France 72/217 [22] Filed: Sept. 8, 1971 921,749 5/1947 France 72/388 PP -l 1 8,631 Primary Examiner-Charles W. Lanham Assistant Examiner-M. J. Keenan 52 US. Cl 72/296, 72/217, 72/318 Attorney Agent, Firm-Frank Tmidl [51 Int. Cl 821d 7/00 [58] Field of Search..... 72/217, 318, 388, 149, 154, [57] ABSTRACT 72/157, 159, 296, 474 A forming die is described for producing compound bends in tubing without removal from the machine or [56] 7 Ref ren e Cit d the use of special fixtures. This arrangement is UNITED STATES PATENTS achieved by providing cut-away sections for clearance 3 553 M970 7 Suding et al 72 of the compound bend adjacent to the die.

2:996:100 8/1961 Newhall et al 72/388 2 Claims, 12 Drawing Figures PATENTEDJAH 29 M4 3. 788,1 16

sum 1 0f 2 FIG. 3 FIG. 4

- INVENTOR 36 26 RA YMOND J FAZZAN/ FIG. 7 BY ATTORNEY PATENTEDJANZ I 7 3.7'88.1 18

sum 2 0f 2 INVENTOR RAYMOND J. FAZZAN/ av Q-M ,X T MI ATTORNEY TAILPIPE FORMING MECHANISM BACKGROUND OF THE' INVENTION This invention relates to a system for producing compound bends in tubing, and more particularly, to the forming die which has a novel clearance provision that permits multiple bends without removal of the tube from the bending machine.

The current problem that exists in making tail pipes, hydraulic lines, etc., is to make a bend close to another bend. Most troublesome is the tail pipe, and the usual solution has been to omit half a compound bend while bending the pipe in a standard tail pipe tube bender, and then to form the last half of a compound bend in a secondary set-up, a special machine with tooling just to make this bend. This secondary machine can be costly and the operation very time consuming. Thus, the conventional tail pipe bender lacks the versatility needed by the trade.

The present invention solves this problem by cutting away a portion of the forming die to allow a clearance area for a compound bend to be formed. The form die is not fixed solidly in one position but rotates around a pin, and its operation is controlled by a numerical control system so as to permit the first bend to enter the area of the die that is cut away. The form die maybe positioned prior to a bend as is the tubing by a command from a numerical control card, which is programmed for a particular brand and vintage of automobile tail pipe. Thus, the machine is capable of forming a tail pipe without the need of any secondary equipment, and the need to inventory partially formed tubes is also eliminated.

Other objectives and advantages will become apparent from a study of the following description taken with the drawings in which:

FIGS. 1 through 11 show the sequential operation of a bending machine with the new die; and

FIG. 12 is an enlarged section of the cut-away forming die taken along line l2-l2 in FIG. 11.

Like parts throughout the various views are referred to by like numbers.

DESCRIPTION OF THE INVENTION Referring to the drawings and particularly to FIG. 1, my cut-away die is represented as a pulley with a section removed, generally indicated by 20, having a pcripheral channel 22 to receive the tube 24 which is positioned in the clamp 26. Channel 22 provides an arcuate portion more than 180. The die is rotatable on a pivot or bore 28, and has a boundary 30 which abbreviates a section sufficiently to provide clearance 32 for a bent tube which is defined in the sectional view of FIG. 12 by phantom lines. The boundary 30 consists of flat portions 31 and 33 which meet at an obtuse angle. Flat portions 31 and 33 are located closer to pivot 28 than the arcuate portion of die .20. The clamp 26 has a shoe 34 which restrains axial movement of the tube 24,- but does not impede bending of the tube when a wiper die 36 presses it into the channel of the die 22. Shoe 34 of clamp 26 has an arcuate portion 35. The arcuate portion of die 20 is complementary to and adjacent to arcuate portion 35.

In operation, the tube 24 is advanced to the forming die 20 and secured between the clamp 26 and the clamp shoe 34. In FIG. 2, the forming die is rotated about its bore 28 to the proper position located preferably by a numerical control system (not shown), or manually. In FIG. 3, the wiper die 36 bends the tube by pressing it into the channel 22 of the forming die 20. With the first bend completed, FIG. 4 shows the wiper die 36 returned to its original position and the tube rotated and advanced by the numerical control.

The control system also simultaneously sets the forming die at a new bend position illustrated in FIG. 5 as a setting for a 45 bend. The phantom lines on the forming die in FIG. 6 show that the previous bend would normally have impinged on the die at crash point 38 but for the clearance provision of this invention.

Thereby, unwanted crimping or deformation of the tube is avoided. FIG. 7 shows the sequential step in which the wiper die is returned to its starting position and the tube advanced for the next bend.

In FIG. 8, the tube is rotated180 from the previous position, and FIG. 9 illustrates the forming die reset to a bend position. The second 90 bend is shown completed at the end of the wiper stroke in FIG. 10, and the wiper die returned to its neutral position with the tube advanced further in FIG. 11.

The degrees of bend and tube positions described are intended to illustrate the versatility of the machine. In no respect should they be considered as limitations.

I claim:

1. An automatic tube-bending machine comprising: clamps for clamping a tube in a desired position, said clamps having an arcuate portion; a wiper for bending the tube; and a rotatably positionable die having an arcuate portion more than the arcuate portion of the die being complementary to and adjacent to the arcuate portion of the clamps, and a pluralityof flat portions meeting at an obtuse angle, the arcuate portion of the die having a channel for receiving a tube, all of the flat portions being located closer to the axis of said die than the rounded portion, said die being adapted to position said flat portions during a bending operation to provide clearance for previously formed tube bends.

2. The combination of claim 1 wherein the channel is located on the periphery of the arcuate portion. 

1. An automatic tube-bending machine comprising: clamps for clamping a tube in a desired position, said clamps having an arcuate portion; a wiper for bending the tube; and a rotatably positionable die having an arcuate portion more than 180*, the arcuate portion of the die being complementary to and adjacent to the arcuate portion of the clamps, and a plurality of flat portions meeting at an obtuse angle, the arcuate portion of the die having a channel for receiving a tube, all of the flat portions being located closer to the axis of said die than the rounded portion, said die being adapted to position said flat portions during a bending operation to provide clearance for previously formed tube bends.
 2. The combination of claim 1 wherein the channel is located on the periphery of the arcuate portion. 